Setting The Signal View - NOVOTEST UD3701 Operation Manual

2.4.5 Setting the signal view

Ultrasonic flaw detector displays on the screen A-scan with material depth as horizontal axis and
signal amplitude as vertical axis. Basic measuring value on horizontal axis – it is time between one
start moment (for example, start of output impulse) and another event moment (for example, received
echo-signal). All the other values are derivatives (distance, thickness) and are mathematically
calculated by means of arithmetic and trigonometric dependences and input values of UT waves
velocity, entry angle and arrow of the probe, delay in the prism and so on.
First of all, user must set units of settings and parameters of the flaw detector (Figure 2.21) in
group of settings «Basic»: select parameter of units «SCALE» and set value (µs or mm).
Figure 2.21 – Selection of units for settings and parameters of the device - «SCALE» parameter
Further settings of signal displaying are made in parameter group «Tract».
To make setting the following parameters are to be set:
1. Set gain of input pulse «GAIN», setting range: from 0 to 126 dB, with step 0,1 or 1 dB. Gain
should be set in a way, that echo-signals are within the screen and are not very small (for
example, the highest peak is about 85% of the screen). See Figure 2.22.
а) gain is 98,0 dB
Figure 2.22 – Setting the gain of input pulse - «GAIN» parameter
2. Set time of scanning «RANGE» (Figure 2.23), setting range: from 14 tо 1000 µs. User can
change scanning time by touching screen. For this use has to touch the screen by two fingers
and move them in opposite direction (to reduce scanning time, Figure 2.9) or move fingers to
each other (to increase scanning time, Figure 2.10.
Note – The device operates with signals within scanning time only.
а) µs
Ultrasonic Flaw Detector NOVOTEST UD3701
b) mm
b) gain is 71,0 dB
Operation manual
Page 36